Satellite Internet faster than advertised, but latency still awful

Satellite latency is 638ms, 20 times higher than terrestrial broadband.

The upload and download speeds promised by satellite Internet providers may not be huge, but it turns out that satellite service delivers much better speeds than it advertises.

Satellite's latency has improved too, but unfortunately it's still 20 times worse than non-satellite services.

The Federal Communications Commission today released its latest Measuring Broadband America report, and for the first time it included results on satellite technology alongside cable, DSL, and fiber-to-the-home. ViaSat is the only satellite provider measured. The company's Exede service promises 12Mbps down and 3Mbps up, but in reality it does much better.

The FCC tested speeds at the homes of 6,733 volunteers over the course of a month, in September 2012.

FCC

Satellite merited inclusion in the latest report because newer satellites have greatly expanded the performance of satellite broadband in general. Latency, though, remains satellite's Achilles' heel. The lengthy round trip that data packets have to make between Earth and satellites results in a noticeable delay between the moment a user clicks on something and the moment in which the user sees the result.

This is particularly troublesome for online gaming. The satellite providers themselves admit that satellite is generally only the best option in parts of the country where the other choices are dial-up or slow DSL service. Data caps also reduce the desirability of satellite. If you can get cable or FiOS, that would be the way to go (even if service offered by the major players leaves much to be desired).

"Satellite systems involve the transmission of information over long distances and have correspondingly higher latencies than for terrestrial technologies," the FCC said. "ViaSat had a measured latency of 638ms for this report, approximately 20 times that [of] the terrestrial average."

The average terrestrial service was measured at 29.6 milliseconds latency. Fiber-to-the-home services led the pack. "During the September 2012 testing period, fiber-to-the-home services provided 18ms round-trip latency on average, while cable-based services averaged 26ms, and DSL-based services averaged 44ms. This compares to figures from the April 2012 testing period of 18ms for fiber, 26ms for cable and 43ms for DSL," the FCC said.

Despite that latency problem, the FCC is optimistic about satellite's potential.

Newer, higher-capacity satellites and technological improvements "have decreased latency and improved the quality of satellite broadband service available to subscribers," the FCC said. "While latency for satellites necessarily remains much higher than for terrestrial services, with the improvements afforded by the new technology we find that it will support many types of popular broadband services and applications."

"Beginning in 2011, the consumer broadband satellite industry began launching a new generation of satellites to significantly improve overall performance," the FCC said. "In October of that year ViaSat launched its ViaSat-1 satellite, which has an overall capacity of 140Gbps. In addition to increasing bandwidth capacity, ViaSat and other satellite industry operators have lowered overall latency by making improvements to other elements of their architecture, such as by dispensing with the need to request communication channel assignments, adopting advances in consumer satellite terminal equipment, incorporating protocol acceleration technology, and developing new error correction technology to provide resiliency to rain fade. Despite these many improvements, latency for this new generation [of] satellite-delivered broadband remains high."

With the exception of satellite's addition, nothing too drastic has changed since the last time we covered the FCC's Measuring Broadband research in July 2012. In previous reports, satellite stats were released as part of the raw data but not actually included in the final reports, because the FCC "recognized that the industry was on the verge of a major transition."

66 Reader Comments

Like it or not, satellite is the only option in some places. Since it does not depend on any type of terrestrial lines, is mainly works anywhere where that satellite has coverage.

Boats, mountains, places far away from civilization, well lets assume you are rich and you have your own private island, satellite would be your only option.

In the medium term high altitude solar powered LTE-A drone relays should be able to cover islands reasonably near the coast and a lot of mountainous areas. Up above the cloud deck recharging the batteries shouldn't be a problem and 100km max cell sizes mean even very sparsely populated areas can have enough customers to make it viable and for a residential base station cranking up the transmit power to cover the long range isn't the battery killing show stopper it would be for a phone.

Does Hughes still cut your bandwidth for opening more than one IP connection at a time? They used to cut it at the router they provided customers with by setting an "excessive use" option bit if more than one TCP/IP session was opened in under a second. Most website advertising tripped the option bit.

It doesn't matter if peak bandwidth provided by satellite is great (assuming one can live with the latency). The real issue is satellite providers treat their customers like crap, have ridiculous bandwidth caps and do a bunch of other garbage which is completely intolerable given the vast majority of their customers are captives to their service.

Like it or not, satellite is the only option in some places. Since it does not depend on any type of terrestrial lines, is mainly works anywhere where that satellite has coverage.

Boats, mountains, places far away from civilization, well lets assume you are rich and you have your own private island, satellite would be your only option.

In the medium term high altitude solar powered LTE-A drone relays should be able to cover islands reasonably near the coast and a lot of mountainous areas. Up above the cloud deck recharging the batteries shouldn't be a problem and 100km max cell sizes mean even very sparsely populated areas can have enough customers to make it viable and for a residential base station cranking up the transmit power to cover the long range isn't the battery killing show stopper it would be for a phone.

That would be one idea, but how many drones would you need to communicate land to an island? I assume drones need to be re-transmit data from one drone to another maintain a visual line. The lines of drones in the sky would be visually not appealing, not to mention cost.

Technically speaking I don´t know how viable this would be either, it would need some type of mesh technology that exists today and the biggest problem, which also is real on wifi repeaters is that bandwidth decreases by 50% of half from hub to hub.

The amount of bandwidth lost would be huge. Compare this to 3 point satellite connection. Earth to Satellite back to Earth.

The drone solution would also have a very limited coverage as opposed to a satellite which can cover a whole continent at once.

Now take that connection to a boat in the middle of the ocean or to an island. I would still trust more the satellite vs a low altitude line of drones which is also affected by weather and earth climate conditions.

The reason why this does not exist, is because its to expensive, it would be allot more unreliable and expensive. What can work is low orbit satellites, or very cheap satellites, but drones, I don´t think so, they cannot sustain enough altitude. Google tried some type of weather ballons and that did not went well either which is similar to what you mentioned.

Ah yes, I remember satellite. WildBlue was the provider. Since I live in Hail Alley, I also remember not being able to get Internet when a thunderstorm went by. Our satellite TV dish fared better (and me and my dad calibrated that one ourselves a la "Can you hear me now?" type fashion), though wouldn't be too far ahead.

I also remember the data cap. If you shot past it (we did more often than not) enjoy expensive-ass dial-up for a few weeks. That in that, the latency sucked for online games. I remember trying to play NCAA Football (I think '08) and got frame-by-frame action (I s**t you not).

Lucky for me, I had Alltel cell service and EV-DO service. 15 miles from the nearest cell tower compared to 22,000 miles for the satellite relay. Also, had service during thunderstorms and had unlimited nights and weekends. Combine that with all Alltel charged you was minutes and weekends with Halo for PC was fun. Little lag, fast enough to not be slow. Graphics-intense websites could be slow since we were a decent distance from the cell tower, but could go head-to-head against satellite any day.

I remember our top speeds: 1.5 Mbps down, 512 Kbps up (on a good day). While we had WildBlue, something went wrong with our dish to where a bird would disrupt out connection. We actually don't know what caused it, but the Internet would go out for no reason on a calm day.

I guess what I am trying to say is that satellite kinda sucked, even compared to dial-up. I've had both. In fact, I prefer Verizon's data cap to satellite's any day. Verizon will charge you more, but at least they don't cut your speed like satellite would (and still does).

I live totally off grid. For years we had a pair of old Clearwire modems bridged, which combined got us ~3Mbps/500Kpbs with 200ms pings. Unfortunately Clearwire is decommissioning the tower that serves our area. The newer 4G service doesn't quite reach us. We tried to get EVDO, but even with an antenna on a 50' pole the signal dropped out every few seconds.

We got Excede (WildBlue/ViaSat) a few months ago when we heard Clearwire would be going offline soon, but it's unusable for us. It probably works fine for "normal" people, but it's an awful solution for us. My partner watches a LOT of video and I am a web developer that deals with 1000's of tiny files every day.

My rough sense of things is transferring one 100MB file takes a minute or two. Transferring 100 1MB files however takes a 15 minutes and transferring 1000 100KB files can take hours. ViaSat has some slick technology for accelerating HTTP traffic, but it's apparently useless for other protocols.

We're moving next month because for us Excede is simply unusable for us. We'd hit the 25GB data cap in a week, not a month, and my usage is painfully slow because of all the small files.

Verizon Home Fusion is supposed to be "coming soon", but it's got the same data cap issues as ViaSat. If I could chose those I'd take Version Home Fusion over satellite instantly.

This reminds me of that Louis CK bit about how we don't appreciate technology, and the guy sitting on the airplane with his new laptop who gets angry because their WiFi goes down.

You are beaming megabytes of data into space! Directly to a satellite! And it's sending it back to you! I can't believe it works at all. It's like a gigantic neighborhood WiFi that covers billions of people at once. Imagine if we had a space telescope hooked up to one of these things -- we could just beam megabytes of star pictures down to ourselves in almost realtime...

This reminds me of that Louis CK bit about how we don't appreciate technology, and the guy sitting on the airplane with his new laptop who gets angry because their WiFi goes down.

You are beaming megabytes of data into space! Directly to a satellite! And it's sending it back to you! I can't believe it works at all. It's like a gigantic neighborhood WiFi that covers billions of people at once. Imagine if we had a space telescope hooked up to one of these things -- we could just beam megabytes of star pictures down to ourselves in almost realtime...

In other words be grateful for what one has. Flip side, if we didn't have someone saying, "this horse is too slow" we'd still be commuting via horse and buggy.

The satellite providers themselves admit that satellite is generally only the best option in parts of the country where the other choices are dial-up or slow DSL service.

I don't see a scenario where a satellite service would outperform DSL. I'd take 512Kbit DSL over satellite any day of the week.

Yes, you get higher nominal speeds, but you can't use them for downloading big stuff, since you'll hit your caps very quickly. But for basic browsing, the horrid latency is much more of an issue than the bandwidth itself.

Mobile users: those in RVs would be fine with it. When you use cell phone plans you can still be out of range or roaming (eg when in Montana you can end up on Canadian tower, and rack up charges pretty easily). Satellite eliminates some of those. The bandwidth listed above is pretty great considering, and while Skype/FaceTime is out, plenty of other stuff would work. I'm not sayin the RV is a great market, but they have money. I know one person who actually has two locations and they just move there Sat TV between te two rather than paying for a second line they wouldn't use (only one ever gets used, so it's effectively a waste of one entire line).

This article doesn't explain the reason for the latency as well as it could. After all if radio waves travel at light speed then the trip time between satellite and ground shouldn't matter much.

If the satellites are in geosynchronous orbit then its about a 70,000 km round trip. Dividing by the speed of light, we get a minimum latency of 233 ms.

In his defense, that explains a latency of about 300ms (I get about 40-80ms on my cable connection). Where does the other 300 ms come from?

Every TCP packet has to be ACKed. Worst case would be ACKs for single packets adding up to two up and down trips per info packet. Some of it can be reduced by compressing the time delays between packets by the download source always sending up to 6 packets with MTU loading up to max for every transmission and using one ACK for 6 packets.

Besides the poor latency which is especially painful on websites with a lot of different URLs embedded in them, there are the data caps. I have Hughesnet currently. I get 1M down 256k up with a 15GB monthly cap (at 500MB per day). The equivalent on the new Gen4 10MB down with 2MB up and a 30GB monthly cap (at 15GB in one day). All this means is that I arrive at the data caps 5x faster.

And depending on the protocol used (TCP as an example) you may have to double that time because the packets have to have acknowledged before more are sent which can effectively double your latency.

Uhh... No. Look up TCP Sliding Windows. You might get one ACK for every 50 packets, not 1:1.

Well, unless you play Warcraft or something, and have run Leatrix, or manually turned Windows ACKs back to 1:1. Can't have the server waiting for confirmation the last 40 packets, that you won't acknowledge until you get 10 more. You have to do that for gaming (well on XP you do); the difference is night and day.

And I saw a couple of comments to the effect of "games have to be made to account for that latency." Well, yes and no. Obviously some parameters must be set, otherwise the guy just outside of Blizz HQ owns the arena. But that's pretty much the way it is anyway. You hit a spell, that command goes to the server, where it's executed; the server then sends back the results, and you see it happen.

With a latency of about 40ms, the whole thing happens in under a tenth of a second, which is close enough to instant. At around 200ms, you feel like you're mired in molasses and the game starts becoming unplayable. Well, for spoiled dandies like me it does. Service people play from Iraq with 1 to 3 seconds of latency. They can cut flowers, level, or even run dungeons with a melee class if you've memorized some of it. Their hits become stacked in the queue, and if something bad happens, they know about it long after everyone else.

They can't do PvP though. If I see your hands waving and glowing, and I know something bad is going to happen to me unless I put the instant freeze on you, well; I'm screwed with even a 200 ms delay. Can't redesign a game for that if the other players see everything a second before you do. And if you force everyone to the highest latency, then you're not doing real-time combat anymore.

This article doesn't explain the reason for the latency as well as it could. After all if radio waves travel at light speed then the trip time between satellite and ground shouldn't matter much.

If the satellites are in geosynchronous orbit then its about a 70,000 km round trip. Dividing by the speed of light, we get a minimum latency of 233 ms.

And depending on the protocol used (TCP as an example) you may have to double that time because the packets have to have acknowledged before more are sent which can effectively double your latency. I realize this is also an issue with any other internet connection, but with satellite it can make the latency feel much worse than what you would mesure it being for a single packet.

A modified version of TCP/IP.

Anyway how about LEO?

I have no idea what these guys use, but many used a protocol called Control OLOHA which was developed back in the 70's. It allows for far more control over the pipe in that you can use 100% of it (or as close as possible by creative timing and removing retrans/collisions).

I gamed on satellite (used to get it for free so I gave it a shot) back in the late 90's and it was terrible. Back then I think I was getting maybe 1100ms pings, but for web it was fine. The beauty of satellite that most people don't get is that it's multicast. Can you imagine doing 14 MPG2 SD streams to millions and millions of people for a few hundred thousand a year (give or take)? That's all it costed back in the day...

The improvement in latency is just because the satellites can switch on their own now so you no longer need a "hub" which the data passes through. You can have multiple down locations to direct the traffic rather than everyone having to route through the hub (both ways) to hit the internet. In the old days (< 99) the request would leave your PC, get packed up, shoot up to the satellite, bounce to the hub, get unpacked, then dumped out on the net. This process repeated for return traffic as well.

638ms for geostationary satellites is not awful, it's actually quite good. 477ms is the absolute minimum if you're on the equator, directly beneath the satellite. At 45 degrees North, in the same meridian of the satellite, it's 506ms, so a more realistic lower bound is something around 510ms.

Speedy or not, until they come up with some pricing structure that doesn't curb-stomp your wallet for a decent amount of monthly bandwidth, I'm still uninterested. Living in a rural area, I was absolutely ecstatic that I got to sign up with Charter instead of being forced to use satellite (I know, right?).

This article doesn't explain the reason for the latency as well as it could. After all if radio waves travel at light speed then the trip time between satellite and ground shouldn't matter much.

If the satellites are in geosynchronous orbit then its about a 70,000 km round trip. Dividing by the speed of light, we get a minimum latency of 233 ms.

And depending on the protocol used (TCP as an example) you may have to double that time because the packets have to have acknowledged before more are sent which can effectively double your latency. I realize this is also an issue with any other internet connection, but with satellite it can make the latency feel much worse than what you would mesure it being for a single packet.

A modified version of TCP/IP.

Anyway how about LEO?

I have no idea what these guys use, but many used a protocol called Control OLOHA which was developed back in the 70's. It allows for far more control over the pipe in that you can use 100% of it (or as close as possible by creative timing and removing retrans/collisions).

AFAIK, some TCP/IP over satellite solutions spoof the TCP ACKs at the router/ground station and use the link layer to ensure reliable transmission of data.

While a "constellation" of fast, lower-orbiting satellites can reduce latency, there are still many technical problems to be overcome - foremost, you need a LOT of satellites. The constellation approach is basically an inverted cellphone architecture. The users are stationary and the "towers" are moving. If polar orbits are used, even more satellites are required as the Earth rotates under the orbit of the satellite.

Fortunately, there just isn't any crying need for instantaneous response. Gaming is not a a vital application. Sophisticated deep-space missions are performed with extremely long latencies. I, for one, am certainly not willing to pay a premium so that gamers can play on isolated mountaintops.

To put things in perspective, the latency of the human visual response system is on the order of 100ms.